Celtic vs. Juventus

Group stage: Celtic finished second in Group G behind Barcelona; Juventus won Group E

Scottish champions Celtic pulled off one of the most surprising results of the group stage by beating Barcelona at Celtic Park in November.

Neil Lennon's team held only 16 percent of possession in that match, and although Juventus won't hold the ball quite as much as Barcelona, Celtic will likely employ similar tactics to the defend-and-counter style they used against Lionel Messi and Co.

As usual, then, Andrea Pirlo's contribution in the Juventus midfield will be key. The 33-year-old playmaker was an injury doubt after straining his thigh on international duty (via Daily Mail), but he started Juve's 2-0 win over Fiorentina on Saturday.

Should the midfield maestro not suffer any ill-effects from that match, the Serie A leaders have plenty of options in the attack. Fabio Quagliarella, Mirko Vucinic, Alessandro Matri, Sebastian Giovinco, Arturo Vidal and Pirlo have all scored five goals or more in Serie A this season.

With his team leading the Scottish Premier League by 18 points, Lennon rested several first-team players at the weekend against Inverness. Greek forward Georgios Samaras remains a question mark with a thigh problem.

Prediction: With all the quality in their squad, the Bianconeri will be favored to advance over two legs. Celtic, however, have won 21 of 23 home matches in the Champions League (per Goal.com), so look for this first leg to be a tight match. Celtic 1, Juventus 1

Former England captain David Beckham, who signed with PSG on transfer deadline day last month, has yet to feature for his new team. The 37-year-old midfielder is expected to make his debut against Marseille later this month.

Valencia, who sit fifth in Spain's Primera Division, have no major injury concerns. Spanish forward Roberto Soldado has scored 16 goals in all competitions this season, including four in Europe.

Prediction: Valencia won twice at home in the group stage and drew 1-1 with group winners Bayern Munich. The Spaniards have recovered their form (somewhat) in the league under the guidance of new manager Ernesto Valverde. PSG won five of six in the group stage but lost 1-0 at Porto on Matchday 2. Expect a similar upset in favor of the home side. Valencia 2, PSG 1

Shakhtar Donetsk vs. Borussia Dortmund

Scott Heavey/Getty Images

When: Wednesday, 2:45 p.m. ET

Where: Donbass Arena, Donetsk

Group stage: Shakhtar finished second in Group E behind Juventus; Borussia Dortmund won Group D

Dortmund's German winger Kevin Grosskreutz has been ruled out with a suspected case of pneumonia. Midfielder Ilkay Gundogan (thigh and toe) is questionable, while defenders Neven Subotic and Marcel Schmelzer are expected to return from injuries (via Football.co.uk).

Shakhtar will be weakened by the sale of Brazilian midfielder Willian (pictured, right—four goals in the group stage) to Anzhi Makhachkala of the Russian Premier League (via FIFA.com), but plenty of talent remains in forward Luiz Adriano (three goals) and attacking midfielder Henrikh Mkhitaryan (two).

Dortmund impressed in the group stage, beating out Real Madrid, Ajax and Manchester City to top spot in Group D, the so-called "Group of Death." But Jurgen Klopp's team lost 4-1 to Hamburg at the weekend in the Bundesliga. In their last 19 Champions League fixtures, Dortmund have kept just one clean sheet.

Prediction: If there is a good time to catch Dortmund, it's now. But will Shakhtar be strong enough following Willian's departure? Here's guessing the answer is both yes and no. Shakhtar Donetsk 2, Borussia Dortmund 2

Real Madrid vs. Manchester United

Group stage: Real Madrid finished second in Group D behind Borussia Dortmund; Manchester United won Group H

This is it, "the match the world is waiting for," according to Real Madrid manager Jose Mourinho (via Daily Telegraph). Really, it's hard to argue with him.

Real Madrid won Spain's La Liga last season, beating out Barcelona, but this season Mourinho and company are struggling domestically. Portuguese superstar Cristiano Ronaldo, now 28, faces the club at which he made his name and took his first steps toward superstardom.

United lead the Premier League table by a whopping 12 points over defending champions Manchester City, but that doesn't mean the Red Devils have taken it easy lately. Manager Sir Alex Ferguson selected a strong team at the weekend against Everton. The decision paid off with a 2-0 victory, but the question remains whether United's squad will be fresh in Madrid.

Real have not kept a clean sheet in the Champions League this year, but United have never won away to Real Madrid in four matches (via Yahoo! Eurosport).

Ferguson says the pressure is on Real (via ESPN FC), and he's probably right. But Ronaldo enters the match with momentum after hitting a hat-trick at the weekend. Adding extra spice to the match is the history of exciting encounters in England between Mourinho's Chelsea and Ferguson's United. The two now consider each other friends.

Prediction: The last time these clubs met in this competition, the 2002-03 quarterfinals, Real escaped with a 6-5 aggregate victory over two legs. With both teams boasting so much firepower, another shootout is likely in store. Despite their struggles, Real could be dangerous at home. Real Madrid 3, Manchester United 2